This invention relates to a bearing seal and, more specifically, to a seal for a self-aligning bearing.
Bearing assemblies are utilized in a wide variety of applications, including those in which the operating environment contains elements which are detrimental to the operation of the bearing, for example, dirt, grit and other particulates encountered in agricultural applications. If such particulates make their way into the bearing assembly and deposit on the bearing surfaces, these particulates can cause damage and substantially decrease the life and efficiency of the bearing.
Certain self-aligning bearings, for example, the bearings disclosed in U.S. Pats. Nos. 3,311,429 and 3,314,735, provide additional problems in that relative movement takes place between the bearing housing and the bearing outer race. The surface over which relative movement takes place must also be kept free of contaminants.
The prior art contains numerous examples of seals for bearings. In the aforementioned U.S. Pats. Nos. 3,311,429 and 3,314,735, there is disclosed an annular bearing seal on either side of ball bearing elements and between the inner and outer races of each bearing assembly. The outer periphery of each seal is secured within an annular retainer which is press-fitted within the outer race of the bearing. The inner surface of each seal defines a central hole and includes three lips which are directed radially inwardly and which contact the inner race of the bearing. When installed in the bearing, the three lips are pushed and held in axially outwardly direction by the inner race. The axially inwardly and outwardly facing side surfaces of each bearing seal are generally flat and are encased in a retainer.
In a variation of the above described seal made by the assignee of this application, an annular metal retainer contains an elastomeric seal and secures it within the outer bearing race. This metal retainer comprises a turned-over lip which mates with corresponding grooves in the outer race. The retainer is attached to the seal along the seal outer peripheral surface and axially outward side.
In short, many of the known designs mechanically lock the seals into the bearings, frequently requiring crimping of those seals into mating grooves formed in the outer ring.
While such sealed bearing assemblies have exhibited improved life in difficult environmental conditions, such assemblies have been complex and costly to manufacture and assemble in conventional antifriction bearing applications.